Nesting aggregations: SUM(AVG())?

[imik]

Hi, 

I'd like to ask for help with the issue I am currently dealing with.

I have two calculations 

1.sum(if(MNTH_ULTIMO_FLAG='1',(ACTUAL)))/sum(if(MNTH_ULTIMO_FLAG='1',(MTD_PLAN))) 
2.sum(if(DATE(CAL_DATE)=Date(Today() -1),(ACTUAL)))/sum(if(DATE(CAL_DATE)=Date(Today() -1),(MTD_PLAN)))

and I need to put them into one if expression: if I select in the filter for example "2017-Jan" than I need 1. and if nothing is selected I need the bar chart to display 2.

MNTH_ULTIMO_FLAG='1' is the last day of month

Actual and MTD_Plan numbers should be only for either last day of the month (MNTH_ULTIMO_FLAG='1') or yesterday (Date(Today() -1))

Thank you for advise. 

imk